User accounts are used in various services to enable providing users with customized services. For example, a user may define in a newspaper subscription user account, whether she is interested in sports news. In case she isn't interested in sports, the newspaper may remove sport-related headlines from hypertext transfer protocol, HTTP, information transmitted to the user.
In accounts relating to industrial processes, each operator may have a set of preferences defined for him to enable seamless and low-stress interaction with machinery. For example, a supervisor may have defined in his account information the modules of a nuclear power station control program to which he has access rights. Thereafter, by logging on to his account, the supervisor may be presented with control panels relating to the modules to which he has access. In such a case, the supervisor needn't separately log on to the modules, and the modules may be initialized with his preferences. As supervisors may work in shifts, each supervisor may have different preferences to facilitate seamless work.
In some processes, the set of users that have access may be limited by a purpose of the process. For example, only authorized users may be given access to a corporate safety data network. In some installations, magnetic tokens are distributed to legitimate users to enable their access to the site. In other installations, fingerprint readers are used to enable access to the site for legitimate users. A database of fingerprints of legitimate users may be stored centrally or at fingerprint reader devices.
Some devices are designed to be used only by adult persons. For example, life rafts aboard passenger ships may be designed to be easily usable by adult passengers in case of emergency, but to not be usable by children as playing children might otherwise inappropriately trigger the rafts. For example, the triggering mechanism may be placed high so that a child cannot reach it, or the triggering mechanism may require muscle strength only an adult will have. Steering mechanisms of cars are built so that a small child would have difficulty using both the pedals and the steering wheel at the same time due to his small size.